------------------From: Eric W. Biederman <ebiederm@xmission.com>commit 05d81d2222beec7b63ac8c1c8cdb5bb4f82c2bad upstreamI had 8250.nr_uarts=16 in the boot line of a test kernel and I had a weirdmysterious crash in sysfs. After taking an in-depth look I realized thatCONFIG_SERIAL_8250_NR_UARTS was set to 4 and I was walking off the end ofthe serial8250_ports array.